Sahih Bukhari Volume 3, Book 49, Hadith 2524

حَدَّثَنَا عُبَيْدُ بْنُ إِسْمَاعِيلَ، عَنْ أَبِي أُسَامَةَ، عَنْ عُبَيْدِ اللَّهِ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما ـ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ مَنْ أَعْتَقَ شِرْكًا لَهُ فِي مَمْلُوكٍ فَعَلَيْهِ عِتْقُهُ كُلِّهِ، إِنْ كَانَ لَهُ مَالٌ يَبْلُغُ ثَمَنَهُ، فَإِنْ لَمْ يَكُنْ لَهُ يُقَوَّمُ عَلَيْهِ قِيمَةَ عَدْلٍ، فَأُعْتِقَ مِنْهُ مَا أَعْتَقَ ‏"‏‏.‏ حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا بِشْرٌ، عَنْ عُبَيْدِ اللَّهِ، اخْتَصَرَهُ‏.‏

Narrated By Ibn 'Umar : Allah's Apostle said, "Whoever manumits his share of a slave, then it is essential for him to get that slave manumitted' completely as long as he has the money to do so. If he has not sufficient money to pay the price of the other shares (after the price of the slave is evaluated justly), the manumitted manumits the slave partially in proportion to his share. Narrated By 'Ubaidullah : As above (briefly).